SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dae3629ef9b869a586cdddf167e0a3d1377bd4cac52df3e114a91ebdd800b06' 
  AND token = 'RYvi/XlQWiunrmCfePgHSL7vY5nsI4sXp30UChk6xOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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