SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87fe6e745a886be7ae87464ca69ee5786dd8e04e81966831604e7d924139c60a' 
  AND token = 'Rw048hRlW1Jic74FdE/jsMewnkrhNl3lsJCwKOYtE0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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