SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af476b132577cb2d26076d5cda86fdeb0a71ee397dc3396667ab130639e6a2a2' 
  AND token = 'ySDQotK++XifWNFV3thMNkGYmYHNGhngZNiVrHJHduo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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