SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f545556fa81a8820ad4d41547898efdf154ab24698ff84e9bca3bbf12e95ce70' 
  AND token = 'qbD7FfqXhKuAGwFL6tDvOibjv9liI4Nol+lD4Mj5Wbc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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