SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '264a8dba20dfe5bdc824bc3a40c226d9c38fe122f8909f45b057b571a6ef4a19' 
  AND token = '7Fh+YBvV7tStTIlqcxk9GBCLkLlSIC+zh2C/0M6PT4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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