SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5d82a9009b02fad879fdb8d879ac75da3c12e7de12af5e28c25c8562f85a1e6' 
  AND token = 'Mi0vI7utz6KrpsKigwM0N41cqao9cfZMnH4yQbIW7pc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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