SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dde4a6f1f36337daf88acd01b7389fc138600bdd8301d34bea1cd916b71183e0' 
  AND token = 'ZGVTFg+GTS1EEeeV34AaiAhyYtf3wQD+gKmWRHFvDso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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