SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f82b6ed547259e2623dddb8a4dab771d38cd630c0314ab261e298af44cd5d270' 
  AND token = 'uIYRw8RjFQEH0jw/dCwM1QbqnH9XwcPQuO8DWdh7b+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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