SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e919b46cf62c1c46d77e52332e852b1ca6e6a0cc286b675b4441e4a3b2d425df' 
  AND token = 'OI+/phXjg6OyheQPZsLuKVBHWG4t0UZfzu4WNcuDTy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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