SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69bfc5941bd90625c57c6cc689129b39f389debc96bae73994bbd03113c08a60' 
  AND token = 'P+BMqMMNPlbtAqaQdWvIE05FCWMBzJVrkMvkJ0N1wvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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