SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfe609490fafd4ebbb3a1777b0daecd49f8ba4dc14dfbb25b175a4d20e6c4546' 
  AND token = 'naccW+GJIUY/XBYiRCOoEvWS4OM2I0syWIfS3HKxK0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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