SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8d03780d0618ab61d481a74845fefaa97a6eeb5f25f6d4d91b4347675f21229' 
  AND token = '2bKoj2bBRDJJ3nS6l7BLtKlHcYmSPBQRl6H1y5El7Zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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