SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '785f92c82457fe3a25e08890c6e12c63e2341f262ce221a8e25925d0e1301f77' 
  AND token = 'XwU514PO9bYOFLojR2C3GmujhpGHBoXtN6pqB2wagKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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