SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '247a90674cbe7f1c623cab4f97bd10186ca7d31b8ed82284eb3eb6ebfbe2ff18' 
  AND token = 'Wz/BRqbAmnAqxCQNyfXsuE1p+wJjIK+MtsUYJj55ci4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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