SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fac103aa58bbd04a44cf7851d63b28dfc88b6d2e292b28f40369dea5956b7ce' 
  AND token = 'irxBMqCCGCJJ1yRPEwqIImEcVyhaOJ3tvMH35SygEPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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