SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bbdf839ce48e56fadbe7ef335e24a2ac4e3b0d959558110dcf0b2dc7c22fdc3' 
  AND token = 'mUYXeifGEkXPS0RLg18l69dN2n1ttJPCJyWYc7o9X8A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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