SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11fbde418556aa9d590094b30786f12f14bbc5bea9710a137f153d92ad8a067f' 
  AND token = 'f7lzQgg+567MuddawNSeKvXR+10gau1l2c+PFQhBCtI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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