SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '338381f6c2e9b446019de29df9db903d58ae2d7e0a97b92191e0416b946189a8' 
  AND token = 'FUPUETecbTbdgH89gvPXTEzcfNVdoTE3/Zj4oVn1ENA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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