SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '700243246f45c2c45a1e4266f3d28d439cc54d2f1236803877afbf7031b3d151' 
  AND token = 'qwHs1tPoctE1VcFDDu2vIOJ2MCgjW4pHqaY0kfK6oxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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