SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3e7c77132f1ffa2d1ac3319f7ca8b28bb1b3cc4e58dda03f13203270a97a81a' 
  AND token = 'DaIU7eCYMasrYKKFFIFvfWNPsvruN07bfWcBz1vcWTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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