SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a7e911e9ebc91e6eb56924720ce636dddf7c398fead1734f2d821020985403d4' 
  AND token = 'yE35jKMaYH5cDLDrevjpW5VTjUY+vNxNWiFJjcdAMdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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