SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13b80b913c143d481ab21f1f99bf4164b563e70b4594e95565c71629a44cee48' 
  AND token = 'dObmoJqJY5Q0iKGVZBzv63vKd8gd4Pdfl5G1juKlRy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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