SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b1d412303deaf82fdf4861884192782974687a7546776669f84dc1cda6fd4756' 
  AND token = '/CBY2BM3pIOcK/+mK5pxZ++aWJBhOmN772q4m33e88Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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