SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd42d0f94791cf29e327c52312c6bce9943c4e2a06f70c6154b047ded474ee387' 
  AND token = 'MDMr7f65UwjpZTOTgsdbGTXHAG0M9E952RqHbBEJC7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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