SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c864c93ab06a0e47be7a215eb2fbb18856eb944686f248a485d75415534d5826' 
  AND token = 'jpAaJkE9SozYiPsuDOZkLJVQwUKlIdFUCEj2hqp6OXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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