SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '984f0953e0706d8446f09dff00002683c0a00d0cfad3b521dca58d9e9ba766d3' 
  AND token = 'rdk57tcKA+QQYfj2N3w/URTFSVNa5AI9sFa8t+x7QnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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