SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f3d0447af6b5d63f39be3c9fa280d8a5de61b0bcc6724d19f78e7855677dde10' 
  AND token = 'N5v34HGKDrNjuhzd0UXTOPzVs/Ex2izUpbM1oSGpsXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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