SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '897d4312e5a3b0f71f10d7a52036b21848f80ca7a2282fd87e6cfb9d9c4b8638' 
  AND token = 'u8LMHWKWhVAwdlAaUtqU/3T2ZcGSmoP5l/ZBXP4HGPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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