SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbdebc4c0823978ae1a13d997a8a2907e87aedb4bd440cdbb66619916436f100' 
  AND token = 'lqWU7X5Bx8jAYt5KTQmh1QCnBTwoIeEIG8K604+H2B0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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