SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa75957cbf9d6f3b48d06a4200f4d11f1e1d8436d7123ae305c62d75cce8b761' 
  AND token = 'cT0GNBWRNHHq6ZZSFD7b/ptyNcbv9VNtq457q3CPQCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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