SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '341deed9a8c1fb94b31c82c2ed2bdb675cc296e73046dce88dab2b775a925494' 
  AND token = 'usBvgo7UyjcBDS27OS1kFZX3sQB/CWfZ4HPOMx4B5Eg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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