SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ba80e1765d697e99900eb7d1b1a93866a284c6d34841ae247d74909266a6f29d' 
  AND token = 'F0B/+CEB8uaGvDtUu5SPjiqXAb0q+w5JMNzFo2JGTCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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