SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c74445d1ef2b30d9f0adcd932ac7aaf3d44e0917c9679d98b422e88574eeb1a5' 
  AND token = '8/dHdjOrULOILJ5yJSvZwcRpOk7ms2vx5o44mo+hUBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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