SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '813ffdc6bb84ef1f9faad82b826a9d53e41833290b604a5338adaa54c9db0509' 
  AND token = '26v/St4jKnBj28dYTLpxEQ6Rk5R/fYUZ9xhZlf8akkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}