SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '342d675cadd31e2d93bda2bd23daaef084eb3a7675bd3bed700046b58136f32f' 
  AND token = 'MP372fbe1pKywiLIaxJWFGmoj3hFw4ubgQ0AWDF9TBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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