SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e80812a259f110f0dae0281250c57b3da2381929f5824998090b3c87704ab25a' 
  AND token = 'lfK6nybuJLXxkkGiWl0ILoW1E8U8minKi0+dbS4sTjE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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