SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdbbc885f4acc9992afe63f4b0d4bce318e6a0a99d7726f444671b5c308e2ff9' 
  AND token = '3rcUPJFPnpB8LLUxVhj621hKMjokhqW2GMzhPYxKw2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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