SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04c0b71392cf63df68b55387be349ebf45230655e1b2b11fa45a6333a7023b16' 
  AND token = '+mJkKfNX6nZmRSnoQbqhPF458aVzdBlpYPvjIMIzq70=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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