SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '597c29bec96968de204fa5afe0fe119d0b140e672ed0dddb5c61d13ebcb825e6' 
  AND token = '0T3hAMV9Fnk7UXVl83fL+l3yxQOYKoDrbLIOIrK0Gxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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