SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3afa48dba6387f3ff81eae7ada48e9fefed18361d7aaa46fb0111453365b45a1' 
  AND token = 'HwiUut5L9bL0o6CLXpm9boWCwUtgzhcVXKB/OgZrg9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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