SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'deee3a1547ed1c20293af93f24d3e7e48380f7da86588b11caac8228d7e31020' 
  AND token = 'aNlennuoeAsZrtiuH5AEKrQe7o12+WRS7PDyQLZZI7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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