SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0c5b375dfafecfc9a338220cdaa91266e37faaa1c79561228c9898038f4404b' 
  AND token = 'ZVpWEAN5JJtOL2t5pFhLzVUTJ7EXbyJsgpUjXBWk1m4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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