SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d49d0a96eab031db4bca7f8898d3efb538862aebe23e8cd5d83540d703445f9' 
  AND token = 'JWTUsBHcLyce166LmqJWD4GY4gFevsLluGtKDQHjSm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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