SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26f286023cabdd00e888faddda0892adf2cb041457b3dd7fa48cbc25a9d6f509' 
  AND token = 'PCj43pCTgnvGGzQFRj3NSQMR8ZLsL02+RNRzxWgO8Cw=' 
  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"
    }
  }
}