SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f831a0f5353cd62b9a6a565c9ad81a22a345d2d180f59a83384dbe37372328b8' 
  AND token = 'PJVHqDVCe5jo+CL9Q+vLhWvVCsuM7y2uthl2vTE5/Vs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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