SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '257fc74b86704ae5d920eb97a80ff011a132536d1d8c4498d1c3d0f746b8a811' 
  AND token = 'GNh8ZpfzPKNiO+7SoIaFOqUuEGOIpzMvcs5jTC5k2NY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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