SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '881ebf94b72d6922d72d2a2521a6a633b54f777a52f564aad86bc8d013e4605e' 
  AND token = 'BwD7JCckSPOJIhl11Gm83KfziDkGECpO8xv7XmmzqW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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