SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ee4766b1c1ee761f2f9d84b03a6c12ff86217300cb1b877e0d3c1c7f3d9908f4' 
  AND token = 'KMPhvqs+a3diYg1Pb44Itm9UyHFih7PF8btLBqfOjTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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