SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'f1938e5ee41c956295d5e9fd51b734b9b8821f8b7d410c46b6558ff5ce491d8a' 
  AND token = 'u9Cw52xKXJlClwCebFucEsVBnLBlexNUohjlsQJXWQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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