SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bb96810be6750e463465fd9f31d03c8eb5981b04a8211937a197534312c9d6f' 
  AND token = 'Dsdz1/LwXEZ7dZdTJyAsDogBbuHasMINWuhmhH6xDlc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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