SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '341aed87116db4eb65a1c5a3cec9c9551d6e06ddf0bdeef9ee99f7d057b2fefe' 
  AND token = '8QSJQ8QTfFwCk3nKWOQPhPvjDTxHup27QcrLeHTyl8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}