SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c865c91e909f645ee51732b575018ea02fa4a8ca0bc68030492a1f5235b5016c' 
  AND token = 'kGX8jgDlyE4alDXiROAKf6zu/wUmb5u1dY+pqpGB+zk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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