SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8107f11ac356d725a809dc927377978779a50833de4656b6c0c2239ca414623b' 
  AND token = 'a+nVqCwJA4CfvgP0NLEiDT+ulOUXN6B/D5gmq7CS3BE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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