SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1e7be4e8f859dc149b9544273bb527e7b581814cedc73867780f4ab42e202a8' 
  AND token = 'zuelSLstHO5lGSKr5GSTLqfG7JZzK52eJnddSWE2Cx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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