SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e1cf94a5c1022307e4d2bd29833eb4cbe350110c31a9c2fc8ab36d18f8187821' 
  AND token = 'Z8vox8ZfvJPMGR3CGFF0NHJuhJmSiIQ0AsYnengu5UU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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