SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4810e168e81d5e1b1f1bcb8876124fc1c9e5ec3cfa4d0ba90354ea09d60093f' 
  AND token = '1TIGTDvZjbaDbyPlTVJFubcXuz8/31lWmvAUXBcp2y8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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