SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2322879bf1ec7b2d2b96cab6885bab3174cd793048df77e03e21fa68a506dd24' 
  AND token = '6mdQJENWyRJrhKrtH5wTgLWJywTz+VzCkaeJTq/wfX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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