SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63b47f391217b74d2a7714f295bf6165895898dbc2252618b47b5b34a58fefc7' 
  AND token = 'WP5uQcOLUZlp0PLpBiwWE+MfVSEjqelQ5BjQ0bxKj04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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