SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d1feef4017f85a098c344bf54b6c229651cbeec77829af48f3e880fe1e9392d' 
  AND token = '88RjPaH2bSGYq/Q2oDHYaGKsgohQnkurdaTbMA12V/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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