SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87b86a7d8e9dce3473b72c0d1d52872eb98635fd5e5ceb4ead96814ed281804f' 
  AND token = '1hkccJwUU87Qn7YbUFOdnqR/06ynG5WK7SFQUXG4pY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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