SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ff512b276419034ecd410938eb11b705e992c050fbe3bf692694a7a3cba650a' 
  AND token = '8s9+XCbL/FOKN8/8/whNRloKYjhBp77uU54HCldvtm8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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