SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebedb49abbb3abba438fd326a15ff7749550abb80fe7c5005e1c3cf1ee5a203b' 
  AND token = '9iwQywL/WsnVePd8IoUYHIuU+SCPCtvL/BtVzkOw5m4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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