SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a63f819f5a24cf43fd576d584ed3146d0d8b073e4886226c1bf59d302867f183' 
  AND token = 'Ryq8bx4KGhLgkPGwz+7K43hEvFQNKCdD4W3SiC6CpeY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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