SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '438693c44862ead930713639e82c407adf058632ea031b42b82255c4c1957a0a' 
  AND token = 'i8HiYQd5hMq7wNMqpue+1o5Ph2z4qc8WfXqZxjQ66T4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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