SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83129f2b0976702583e339d95bbca71a7158cfb8667d2accabecef1c0fc9a7fe' 
  AND token = 'mqvBTLhyTj0SNDEGI6stoiwYqa9ow3mpVno5Dgo47ew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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