SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef8c780aa7cd87285be7819a283498ac49ac61214c16dbb7f2b42d0bb21d8905' 
  AND token = 'ian49ul/aXcCcVZ/T9KBsiSQoMVD4puFq5mMm4/nsXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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