SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c1e027853d6fc240bf92bcf92242199fa041f9004aab4fef0077eaa2b9d4559' 
  AND token = 'yP+j/ubxlUbml8uJTenoeyK8qSJm8Y4Eb4ZgrXXqx0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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