SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72a9d17266e52cf082dc710feec9cf0814422aea017ac108477e1516da3bb2a6' 
  AND token = 'dztclpLa1ldtPnPUR+hlDu1PORcqF0XGieKObTJyQO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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