SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e919d77bd5b7a40c2797f03f00316eedd8c250e94f346144652e6209c1173035' 
  AND token = 't+ja89jijxcAUU+WQTCerB6xVdWgJ3Y4WKH4FZoynnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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