SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '55e8ddec5bb993701bf476f6c948b0a24c2a372d1955c5cd1524132f8816d4e0' 
  AND token = 'vjgv15lZLS6EiHkzMSbG/6/VHoYGKKObzgHfuGmQF6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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