SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eddf7ebfe8ae1bce9277937bbbb1157066c08f6c51114c378c9bb7ecfadf0044' 
  AND token = 'oNJracNztTWSpuYMPFb75Ws4MuBwZlzV4l/qtKmrT/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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