SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60da21db2ea5dbd3b6a583254ba35a358100f0196709dd8b1234ff6a706f49c8' 
  AND token = '8qUGcOTiEhR/gE4+EIw8eceufiedFLI+22jnBONOGSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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