SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9056d7540669cc83286034d74e20924a767b02452acc82ede8c3db612d7e9273' 
  AND token = 'ULNmhDxkPRUkTh1500ljbRz/SqgEcRYz6lYTv2rQY9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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